Drawing-board attachment.



R. F. DUEL.

' DRAWING BOARD ATTACHMENT.

I APPLICATION FILED DEC-15,1937.

' 1,288,,849, Patented Dec. 24, 1918.

WITNESSES RALPH FREDERICK I DUEL,

OF DULUTH, MINNESOTA.

DRAWING-BOARD ATTACHMENT.

Specification of Letters Patent.

Patented Dec. 24, 1918.

Application filed December 15, 19 17. Serial No. 207,266.

To all whom it may concern:

Be it known that I, RALPH F. DUEL, a. citizen of the United States, anda resident of Duluth, in the county of St. Louis and State of Minnesota,have invented a new and Improved Drawing-Board Attachment, of which thefollowing is a full, clear, and exact description.

This invention relates to drawing boards, and particularly to anattachment therefor, and has for an object the provision of an improvedstructure which may act in different capacities for causing acomparatively small board to supply the require ments of a larger board.

Another object in view is to provide swinging arms which may be used forsupporting articles, and also used for indicating the vanishing pointwhen drawing perspectives or arcs.

A still further object of the invention, more specifically, is theprovision of a number of arms in connection with a drawing board, whicharms may be rotated substantially in a universal manner, and which carryrotatable extensions acting as stops and as an extended section of thedrawing board.

In the accompanying drawing:

Figure 1 is a perspective view of a drawing board with a plurality ofattachments connected therewith disclosing the invention. I

Fig. 2 is a longitudinal, vertical, sectional view through Fig. 3 online 2-2.

Fig. 3 is a bottom plan view of the structure shown in Fig. 2.

Fig. 4 is a transverse sectional. view through Fig. 2 on line 4-4Referring to the accompanying drawing by numerals, 1 indicates a drawingboard of any desired kind, which may be supplied with any desired numberof arms 2, said arms beng constructed as shown in detail in Figs. 8 and4, though if desired the outer end may be provided with a tray or rack 3as shown in Fig. lcontaining tools. The arms 2 may be used as extensionsof the board for receiving the compass when striking alarge circle, ormay be used to placea vanishing point, as well asfor other purposes,including supports for books or extra paper 4.

Each of the arms .2 is provided with an apertured end 5 as shown inFigs. 2 and 3 and a ribbed or scored end 6, said ribs or scores beingeither radial or parallel as desired. As shown in Fig. 4 end 6 is squareand is provided with ridges or teeth 7 on each face, though if desiredthe end 6 could be made round and the teeth 7 arranged in any desiredmanner, as for instance longitudinally of the arm 2. The teeth or ridges7 are intended to engage the teeth 8 on the stationary plate 9, saidstationary plate being connected to the board 1 in any suitable manneras for instance by screws 10. This plate is provided with an apertureand a recess in which bracket- 11 fits, said bracket having a largeannular flange l2 underlying part of the plate 9 as shown in Fig. 2 sothat the bracket will freely rotate without being removed. The bracket11 is provided with an opening 13 through which the end 6 projects andinto which the end of the set screw projects for'forcing the end 6 ofarm 2 against the teeth 8. The use of the teeth 7 and 8 is to positivelyprevent any radial movement of the arm 2 accidentally and to make itcomparatively easy to lock the arm in any desired position.

The outer end of the arm 2 is provided with an apertured portion 5 asabove described through which a set screw 15 extends, said set screwfitting into the socket member 16 which is secured to the finger 17 byscrews or otherwise as preferred. The finger 17 acts as a part of theboard 1 under certain circumstances, as for instance when a perspectiveis being drawn as shown in Fig. 1., or when a support is desired for acompass. A number of small indentations 18 are provided for receivingthe end of the compass or for receiving a pin, or acting in any otherdesired manner. \Vhen drawing a perspective as shown in Fig. 1 a pin maybe inserted in anv of the sockets 18 and the T-square maintained againstthe same whereby all the angles of the perspective will be properlypositioned. It will be noted that the finger 17 may be rotated aroundthe set screw 15 in a given plane and may be rotated in a plane at rightangles to the first mentioned plane upon the rotation of the arm 2,whereby. the finger 17 may be placed in any desired position as well asthe arm 2.

What I claim is: r y

1. In a drawing board attachment of the character described. thecombination with a board of a plate, means for rigidly securing saidplate to a. board, a rotatable bracket mounted on said :plate, an armextending from said bracket, said arm being movable in a plane parallel,With the board and also rotatable on its oWn axis, means for lockingsaid arm in any adjusted position, and an independently rotatablesupporting finger on the outer end-0f said arm.

2. An attachment for drawing boards, an arm, means for pivotallymounting the arm on a'drawing board,-Ineans for looking the 10 finger inany desired position in relation to 15 the arm.

RALPH FREDERICK DUEL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner ot'latents,

Washington; D. 0.

